DOCSLIB.ORG

Pattern and Gain Characterization Using Nonintrusive Very-Near

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Pattern and Gain Characterization Using Nonintrusive Very-Near IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 65, NO. 2, FEBRUARY 2017 489 Pattern and Gain Characterization Using Nonintrusive Very-Near-Field Electro-Optical Measurements Over Arbitrary Closed Surfaces Kamal Sarabandi, Fellow, IEEE, Jihun Choi, Student Member, IEEE, Ali Sabet, and Kazem Sabet, Senior Member, IEEE Abstract— A nonintrusive near-field measurement technique of course the direct far-field measurement that can be accom- for 3-D radiation pattern and gain characterization of antennas is plished in outdoor ranges or in anechoic chambers [1]–[3]. The presented. The method is of particular interest for low-frequency use of such techniques with low-frequency antennas operating antennas for which anechoic chambers cannot be developed and far-field measurements are rather cumbersome. Nonintrusive, at high frequency (HF) or low very HF (VHF) bands is limited broadband measurements are performed using an extremely by a number of factors. At these frequencies, the sizes of small all-dielectric electro-optical probe to measure the tangential anechoic chambers and the absorbers become prohibitively electric fields of an antenna under test (AUT) at a very-near large. Outdoor ranges require a vast space and tall towers, and surface enclosing the antenna. Far-field radiation is computed the effect of ground must be carefully examined for accurate from a new near-field to far-field transformation formulation using only the tangential components of the electric field over an measurements. Special approaches to measure HF and VHF arbitrary surface. This procedure employs reciprocity theorem antennas have been reported in [4]–[9]. These involve scale and the excited electric current on the surface of a perfect modeling, utilization of aircraft-towed transmitters in antenna electric conductor enclosure having the same geometry as the measurements, design of ground-reflection ranges to minimize scanned surface and illuminated by a plane wave. In this way, the contribution of reflection from the ground, and near-field a full spherical radiation pattern and gain of the AUT are easily computed without expensive computation and truncation scanning. All of these require substantial time and effort to errors. To demonstrate the proposed approach, a miniaturized perform the measurements as well as a specially designed low very high frequency antenna operating at 40 MHz with very-large, expensive anechoic chamber in the case of indoor dimensions 0.013λ0×0.013λ0 × 0.02λ0 is utilized. The far-field measurements. results from our approach are shown to be in good agreement In order to circumvent these difficulties, a nonintrusive near- with those obtained from full-wave simulation and direct far-field measurement performed in an elevated outdoor range. field measurement system [10] using an all-dielectric and very small electro-optical (EO) probe is presented in this paper. The Index Terms— Antenna measurements, antenna radiation advantage of the EO probe is that it can be placed very close patterns, electrically small antennas, electro-optical (EO) system, high frequency (HF)/very HF (VHF) antennas, near-field to the antenna surface where the near field is very strong. For measurements. a nonmetallic room that is sufficiently larger than the antenna and for the antenna sufficiently away from obstacles in the I. INTRODUCTION room, the use of absorbers is not critical. The criteria for CCURATE measurement of fundamental antenna para- setting object distances from the antenna are established by Ameters, such as input impedance, bandwidth, radiation monitoring the reactive part of the antenna input impedance as pattern, and gain is very important for all applications. antenna height above ground is changed and nearby obstacles Knowledge of the actual antenna performance plays an impor- are pushed away from the antenna surrounding. Once a stable tant role in designing real-world wireless communication or condition for the reactive part of the input impedance is radar systems. The simplest way to characterize antennas is observed, it is assured that the field distribution over the sur- face of antenna is dominated by the direct signal. Also at low Manuscript received March 18, 2016; revised November 10, 2016; accepted frequencies, reflection and scattering from dielectric walls and November 27, 2016. Date of publication December 1, 2016; date of current version February 1, 2017. This work was supported in part by the U.S. Army objects are rather low. Hence, the contribution from multipath Research Laboratory through collaborative participation in the Microelec- signal on the probe is significantly smaller than the very strong tronics Center of Micro Autonomous Systems and Technology Collaborative near field of the antenna. Conventional probes, such as loops, Technology Alliance, under Contract W911NF and in part by the National Science Foundation through ECE Program, under Award 1101868. short diploes, or open-ended waveguides, which make use of K. Sarabandi and J. Choi are with the Radiation Laboratory, Department metallic structures together with their connected transmission of Electrical Engineering and Computer Science, University of Michigan, lines, can significantly perturb the current distribution on the Ann Arbor, MI 48109-2122 USA (e-mail: [email protected]; [email protected]). antenna if they are brought to very close proximity of the A. Sabet and K. Sabet are with EMAG Technologies Inc., Ann Arbor, antenna. This is particularly the case if the antenna under MI 48108 USA (e-mail: [email protected]; [email protected]). test (AUT) is electrically small whose dimensions are com- Color versions of one or more of the figures in this paper are available online at http://ieeexplore.ieee.org. parable to those conventional probes. Unlike the conventional Digital Object Identifier 10.1109/TAP.2016.2633949 metallic probes, the EO probe with a very small tip of less 0018-926X © 2016 IEEE. Personal use is permitted, but republication/redistribution requires IEEE permission. See http://www.ieee.org/publications_standards/publications/rights/index.html for more information. 490 IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 65, NO. 2, FEBRUARY 2017 than1mm3 connected to very thin fiber optics does not provide [16], [17]. One such advantage pertains to the mea- perturb the excited currents on the antenna. The EO probe surement of antennas at low frequencies. For applications, used here is also very broadband and can be applied for all such as source tracking [18] and reliable communication in frequencies of interest up to and beyond millimeter-waveband. complex environments [19], [20], an extremely small and Furthermore, the computationally complicated probe compen- lightweight antenna operating at low-VHF band has been sation process [11], [12] is not required, since the EO probe developed. For this antenna, pattern and gain measurements measurement is nonradiative. were carried out in an outdoor elevated range with nonmetallic In [13] and [14], near-field to far-field transformation for towers. A standard far-field measurement setup, in which both arbitrary enclosing near-field surfaces has been proposed. the transmitting and the receiving antennas are mounted on These approaches, however, provide only an approximate top of a tall fiberglass tower (>12 m), was used to create solution under the assumption that the radii of curvature nearly free-space conditions in the far-field region. For this of the surface at every point are much larger than the measurement, considerable efforts are needed because of the wavelength. Similar to our approach, they place a perfect cumbersome antenna setup and scanning. The height of AUT electric conductor (PEC) over the aperture of the antenna above ground must also be chosen to be much larger than the with a surface magnetic current proportional to the measured transmit and receive antennas separation to minimize the effect tangential electric field. Then, they apply image theory that of ground reflection. Uncontrollable environmental conditions, is only valid for infinite ground plane to remove the PEC such as rain, wind, and temperature variations, also add to the and double the surface magnetic current. This is only a good complexity of the elevated-range measurement. Furthermore, approximation if the local radii of curvature over the arbitrary for small antennas, the effect of the feed cables on the antenna surface are very large compared with the wavelength. If cubic impedance and radiation pattern is a major issue and was surfaces are used, the edges do not satisfy this condition. observed during the measurement. A small, battery-operated In fact, there is significant edge current on the PEC, which source module had to be designed and connected directly to the cannot be ignored. It is noted here that the dimension of antenna in the elevated range to avoid the effects of the long the box for the problem at hand is only a fraction of the cables. The complexity in such measurements necessitates the wavelength and image theory cannot be applied here. In this development of an alternative approach that is more accurate paper, a novel exact near-field to far-field transformation for and time- and cost-effective. all types of antennas without truncation errors regardless of Near-field scanning systems are developed as an alternative the size of the scanned area is presented. For this approach, to the cumbersome outdoor far-field range or costly anechoic only the tangential components of the electric field over an chamber facilities. However,
Load more

Recommended publications
  • Design and Fabrication of World's Smallest Submillimeter- Wave
    University of Illinois at Chicago, Electrical and Computer Engineering Department IEEE Antennas and Propagation & Microwave Theory and Techniques Societies Design and Fabrication of World’s Smallest Submillimeter- wave Beam-Steering Radar for Autonomous Navigation Kamal Sarabandi, Ph.D., IEEE Fellow President, IEEE Geoscience and Remote Sensing Society Friday, November 13, 11:00 AM Lecture Center F1 807 South Morgan Street Chicago, IL 60607-7053 Host: Prof. Danilo Erricolo, [email protected] Abstract: Autonomous navigation is considered the next important leap in transportation. Also the applications of autonomous robots in manufacturing, security, military, delivery and service sector, as well as in homes are of significant demand. This calls for the development of advanced lower power and compact suite of sensors for situation awareness, path-planning and collision avoidance. Although optical camera and stereo vision can significantly assist in navigation and obstacle detection, their operation is severely hampered in the dark and in poor atmospheric conditions such as dust, smoke, haze and rain. Ability to penetrate poor weather, dust, smoke, cloth and other low loss but optically opaque material makes millimeter-wave (MMW) and sub-MMW radars suitable for navigation and surveillance. Sensors for autonomous small robotic platforms must be low mass, compact size and low power due to the limited space. For such applications, as the dimensions of the structures are lowered, the standard machining and assembling methods are not suitable because of low fabrication tolerances and high cost in assembly. Difficulties in fabrication of RF front-end systems at very high frequencies also include error in alignment of parts, air gaps between conductive components, poor metal contact, complex assemblies of various parts, integration of active components to mention a few.
    [Show full text]
  • Negative Results in Geoscience & Remote Sensing
    http://www.grss-ieee.org/menu.taf?menu=Publications&detail=newsletter Editor: Lorenzo Bruzzone Cumulative Issue #159 June 2011 ISSN 0274-6338 Table of Contents IEEE GRSS AdCom, Officers and Committee Chairs ............................2 Newsletter Input and Deadlines Editor’s Comments .................................3 The following is the schedule for the GRSS Newsletter. If you would like to contribute an article, President’s Message ............................... 3 please submit your input according to this schedule. Input is preferred in Microsoft Word, Word- AdCom Members ..................................5 Perfect or ASCII for IBM format (please send disk and hard copy) as IEEE now uses electronic Chapters and Contact Information ..........6 publishing. Other word processing formats, including those for Macintosh, are also acceptable, however, please be sure to identify the format on the disk and include the hard copy. GRSS MEMBER HIGHLIGHTS GRSS Members Elevated to the GRSS Newsletter Schedule Grade of Senior Member in Month June Sept Dec March March and April 2011 ...........................7 Input April 15 July 15 Oct 15 Jan 15 FEATURES Classification Accuracy Assessment ......... 8 IEEE GRSS AdCom, Officers and Committee Failing as chance – Negative results in Geoscience & Remote Sensing .......... 15 Chairs – 2011 GRS-29 (Division IX) President Fellow Evaluation Committee IGARSS 2010 BOOK REVIEW Jon A. Benediktsson Ya-Qiu Jin Paul Smits Optical Remote Sensing – Advances Executive Vice President Fellow and Senior Member Karen M. St. Germain in Signal Processing and Melba M. Crawford Search IGARSS 2011 Exploitation Techniques ......................... 17 Vice President for Mahta Moghaddam Motoyuki Sato Information Resources History and Records IGARSS 2012 REPORTS Steven C. Reising Werner Wiesbeck Alberto Moreira 2010 TGRS Best Reviewers ..................
    [Show full text]
  • Advancements in Wireless and Radar Technology Enabled by Electromagnetic Bandgap Metamaterials and Metasurfaces
    Advancements in Wireless and Radar Technology Enabled by Electromagnetic Bandgap Metamaterials and Metasurfaces Kamal Sarabandi, The University of Michigan, Ann Arbor, MI, USA Abstract: Electromagnetics is one of the greatest achievements of physics in the 19th century. Despite its long history of development, due to its fundamental nature and broad base, research in applied electromagnetics is still vital and going strong. In recent years electromagnetic has played a major role in wide range of disciplines, including communications, remote sensing of environment, defense, medicine, etc., with significant societal impact. The growth and vitality in EM research has been fueled by an increasing demand for anytime/anywhere information and data, security, and global monitoring of the environment, as well as significant advancements in other related science and engineering disciplines particularly in computers and materials. Introduction of new engineered materials has opened a door for much innovation needed to propel the wireless and radar technologies in many applications. This lecture will provide an overview of applications electromagnetic bandgap metamaterials and metasurfaces developed in Professor Sarabandi’s group. In specifics, the applications of EM bandgap structures for implementation of super‐directive arrays and super‐miniaturized full‐ duplex radio repeaters will be presented. Substrate mode suppression created by artificial bandgap materials allows for placement of small antennas in close proximity of each other while providing a highly level of electromagnetic isolation. Also some novel metasurfaces such as reactive impedance surfaces for antenna miniaturization and miniaturized‐element‐frequency‐selective‐surfaces (MEFSS) as high‐order spatial filtering radomes, transparent ground planes, non‐absorptive radar‐cross‐section reducer EM skin, will be presented to highlight some of the advancements enabled by metasurfaces.
    [Show full text]
  • Embedded-Circuit Magnetic Metamaterial Substrate Performance for Patch Antennas
    Embedded-Circuit Magnetic Metamaterial Substrate Performance for Patch Antennas Kevin Buell'. Hossein Mosallaei and Kamal Sarabandi Radiation Laboratory at the Department of Electrical Engineering and Computer Science University of Michigan Ann Arbor, MI 48109-2122, USA E-mail: [email protected], [email protected], [email protected] Abstract Magnetic permeability was imparted to a naturally non-magnetic material by metallic inclusions. A patch antenna tested the performance of the magnetic metamaterialas a substrate. The magnetic metamaterialexhibited enhanced )r and E as predicted with acceptable loss-factor levels. Models for predicting p and E are presented and simulations indicate that permeability can be extended well beyond several gigahem with cumnt technology. Permeability in the fi, = 1-4 range is achievable for moderately low-loss applications. Representativeantenna miniaturization factor=-6.4 with efficiency=21-35% 1. INTRODUCTION A. Background and Goals OR low loss applications in the microwave region natural material choices are limited to non-magnetic Fdielectrics. The gyromagnetic resonances limits the upper frequency end of the magnetic region in natural materials occur in the VHF-UHF range, too low a frequency for microwave applications. To our knowledge there is no material available with moderately low loss (Tanti, = 5 < 0.02) and moderately enhanced permeability > 2) for operation deeply into the microwave region. I) Benelfts of Magnetic Materials: The permittivity of a composite dielectric can be engineered for practically any permittivity desirable. In contrast, in the microwave region the permeability of low loss materials is limited to that of free space. High dielectric constant materials are used to achieve electromagnetic scaling and field confinement.
    [Show full text]
  • Dr. Dhrubajyoti Bhattacharya Educational Background
    Dr. Dhrubajyoti Bhattacharya Assistant Professor Department of ECE, Indian Institute of Information Technology (IIIT), Bhagalpur Address: IIIT Bhagalpur, Faculty Room-104, Sabour, Bhagalpur, Bihar, 813210, India Email: [email protected], [email protected] Contact No: +91-7076607596 Ph.D.: Indian Institute of Technology, Kharagpur RESEARCH INTERESTS • Computational Electromagnetics • Millimeter wave technology • Microwave Imaging and Remote Sensing • Metamaterial • Optimization Techniques Educational Background Examinations Specialization Year Institution/University Marks passed Obtained Doctor of RF and Microwave July, Department of Electronics and Electrical Philosophy 2013- Communication Engineering, Awarded (Ph.D.) June, Indian Institute of Technology, Kharagpur. 2019 Ph.D. Supervisor: Prof. Bratin Ghosh. Master of Microwave 2011- Department of Electronics and 81.55% Engineering Communication 2013 Telecommunication Engineering, (M.E) Bengal Engineering and Science University, Shibpur (Now IIEST, Shibpur) M.E. Supervisor: Prof. Debasis Mitra. Bachelor of Electronics and 2006- Department of Electronics and 8.11/10 Technology Communication 2010 Communication Engineering, (B.Tech) Engineering Academy of Technology, West Bengal University of Technology (WBUT). 10 + 2 Science 2006 West Bengal Council of Higher Secondary 84.2% Education 10 General 2004 West Bengal Board of Secondary Education 78.5% JOURNAL PUBLICATIONS 1. Dhrubajyoti Bhattacharya, Bratin Ghosh, Manikant Sinha, and Ahmed A. Kishk, “Mode excitation and radiation characteristics of antennas in cylindrically stratified media,” IET Microwaves, Antennas & Propagation, vol. 14, Issue 10, August 2020. 2. Bratin Ghosh, Dhrubajyoti Bhattacharya, Priyanka Deb Sinha, Douglas H. Werner, “Design of circular waveguide annular slot coupled two-layer DRA for linear and circular Polarizations,” IEEE Antennas and Wireless Propagation Letters, vol. 19, Issue 6, pp. 1012-1016, April 2020.
    [Show full text]
  • The Uncertainties Associated with Rydberg Atom Based Electric Field
    2015 USNC-URSI Radio Science Meeting (Joint with AP-S Symposium) Vancouver, British Columbia, Canada 19-24 July 2015 IEEE Catalog Number: CFP1501W-POD ISBN: 978-1-4799-7818-2 TABLE OF CONTENTS TUP-UA.1P: MATERIAL, MODELING AND ANTENNA MEASUREMENTS TUP-UA.1P.1: THE UNCERTAINTIES ASSOCIATED WITH RYDBERG ATOM BASED ELECTRIC .......................... 1 FIELD MEASUREMENTS Christopher Holloway, Joshua Gordon, National Institute of Standards and Technology, United States; Haoguan Fan, Santosh Kumar, James Shaffer, University of Oklahoma, United States TUP-UA.1P.2: ROBOTIC SPHERICAL NEAR-FIELD MEASUREMENTS AT 183 GHZ .................................................... 2 Michael Francis, Ronald Wittmann, David Novotny, Joshua Gordon, National Institute of Standards and Technology, United States TUP-UA.1P.3: EVALUATION OF MATERIAL CHARACTERIZATION SYSTEMS THAT UTILIZE A ........................ 3 TWO-WIRE TRANSMISSION LINE Andrew Temme, Edward Rothwell, Michigan State University, United States TUP-UA.1P.4: A STEPPED WAVEGUIDE TECHNIQUE FOR THE CHARACTERIZATION OF ................................... 4 CONDUCTOR-BACKED ABSORBING MATERIALS Jonathan Frasch, Edward Rothwell, Michigan State University, United States TUP-UA.1P.5: THE USE OF RANDOM AUXILIARY SOURCES FOR REFLECTARRAY FEED ANALYSIS ................ 5 Mohamed Moharram, Ahmed A. Kishk, Concordia University, Canada TUP-UA.1P.6: 3D MODELING FOR REALISTIC ASSESSMENT OF VITAL SIGNS AND LUNG WATER ................... 6 CONTENT Ruthsenne R.G. Perron, Magdy F. Iskander, Hawaii Center for Advanced Communications, United States WEP-UA.1P: LOW PROFILE ANTENNAS AND ARRAYS WEP-UA.1P.2: A LOW-PROFILE FULL-BAND SUBARRAY CAVITY-BACKED SLOT ANTENNA WITH A ............. 7 COMPACT FEED Mohammad Amjadi, Kamal Sarabandi, University of Michigan, United States WEP-UA.1P.3: A COMPACT, WIDEBAND ARRAY OF COUPLED QUARTER-WAVELENGTH SLOT .....................
    [Show full text]
  • Dr. Kamal Sarabandi the Rufus S
    DEPARTMENT OF ELECTRICAL & COMPUTER ENGINEERING www.ece.seas.gwu.edu ECE Distinguished Lecture Series Dr. Kamal Sarabandi The Rufus S. Teesdale Professor of Engineering Director of the Radiation Laboratory The University of Michigan Recent Research Trends in Applied Electromagnetics Monday, December 2, 2019, 2:00 pm – 3:00 pm Location: SEH B1220 Abstract Electromagnetic theory is one of the greatest achievements of physics in the 19th century. Despite its long history of development, due to its fundamental nature and broad base, research in applied electromagnetics is still vital and going strong. In recent years electromagnetic has played a major role in wide range of disciplines, including communications, remote sensing of environment, defense, medicine, etc., with sig- nificant societal impact. To transform ideas into reality in many of these disciplines, the fundamental understanding of electromagnetic wave generation, propagation, and interaction with their environment over a wide spectrum is needed. The growth and vitality in EM research has been fueled by an increasing demand for anytime/anywhere information and data, security, and global monitoring of the environment, as well as significant advancements in other related science and engineering disciplines particularly in computers and materials. This lecture will pro- vide an overview of recent research trends in applied electromagnetics. In particular the examples of research applications that will be present- ed are drawn from Professor Sarabandi’s research activities. Biography Kamal Sarabandi is currently Director of the Radiation Laboratory and the Rufus S. Teesdale endowed Professor of Engineering in the Depart- ment of Electrical Engineering and Computer Science, The University of Michigan at Ann Arbor.
    [Show full text]
  • Design of Reconfigurable Slot Antennas 647
    IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 53, NO. 2, FEBRUARY 2005 645 Design of Reconfigurable Slot Antennas Dimitrios Peroulis, Member, IEEE, Kamal Sarabandi, Fellow, IEEE, and Linda P. B. Katehi, Fellow, IEEE Abstract—In this paper the design of a compact, efficient and Signal propagation over large distances and in urban and electronically tunable antenna is presented. A single-fed resonant forested environment can take place at UHF and lower frequen- slot loaded with a series of PIN diode switches constitute the fun- cies. At these frequencies, the size of broadband and efficient damental structure of the antenna. The antenna tuning is realized by changing its effective electrical length, which is controlled by antennas is considerable. Techniques used to make the antenna the bias voltages of the solid state shunt switches along the slot an- size small, usually renders narrow-band antennas. To make tenna. Although the design is based on a resonant configuration, an miniature size antennas compatible for a frequency-hopped effective bandwidth of 1.7:1 is obtained through this tuning without spread spectrum system, we may consider a reconfigurable requiring a reconfigurable matching network. Four resonant fre- narrow-band antenna that follows the pseudo-random pattern quencies from 540–890 MHz are selected in this bandwidth and very good matching is achieved for all resonant frequencies. The- of the frequency-hopped modulation. In this paper the design oretical and experimental behavior of the antenna parameters is aspects of compact, planar, and reconfigurable antennas are presented and it is demonstrated that the radiation pattern, effi- considered and the feasibility of such designs is demonstrated ciency and polarization state of the antenna remain essentially un- by constructing and testing a planar reconfigurable slot antenna affected by the frequency tuning.
    [Show full text]
  • Sarabandi, Kamal
    Appendix 2 – page 1 INTERNATIONAL UNION OF RADIO SCIENCE 1. NAME OF CANDIDATE: Sarabandi, Kamal ............................................................................... Last, First, Middle PRESENT OCCUPATION: Rufus S. Teesdale Chaired Professor of Engineering ...................... Position, Organization Director of Radiation Laboratory Director of Center for Microelectronics and Biomemetic Advance Technology Department of Electrical Engineering and Computer Science, The University of Michigan. ........................................................................................................................................................ ........................................................................................................................................................ BUSINESS ADDRESS: ............................................................................................................... Dept. of EECS, University of Michigan......................................................................................... 1301 Beal Avenue, 3244 EECS ..................................................................................................... Ann Arbor, MI, 48109-2122, USA ([email protected]).......................................................... HOME ADDRESS: ....................................................................................................................... 2277 Grayfox Court.......................................................................................................................
    [Show full text]
  • A Millimeter-Wave Scaled Measurement System for Wireless Channel Characterization Farshid Aryanfar, Student Member, IEEE, and Kamal Sarabandi, Fellow, IEEE
    IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 52, NO. 6, JUNE 2004 1663 A Millimeter-Wave Scaled Measurement System for Wireless Channel Characterization Farshid Aryanfar, Student Member, IEEE, and Kamal Sarabandi, Fellow, IEEE Abstract—In this paper, a scaled measurement system designed Deterministic methods are based on the physics of the envi- for wireless channel characterization is proposed and discussed, ronment and wave-propagation phenomena such as reflection, and experimental results are reported. The system consists of a transmission, and diffraction. These methods are generally ap- vector network analyzer, miniaturized -band transmitter and receiver probes, scaled buildings, and a precise computer-con- plicable to any arbitrary environment and are especially useful trolled positioner. The scaled propagation measurement system for microcellular and pico-cellular environments where statis- is designed to operate coherently at the 90.8–92.8-GHz band, tical models fail as the channel is highly correlated to the en- and it provides a dynamic range of 85 dB. As the measurement vironment. Propagation model verification using measured data a wavelength in this system ( 3 mm) is approximately two orders of is a very difficult task considering that all dimensions, coordi- magnitude smaller than the actual wavelength in most commercial and military wireless systems, a typical dimension of the propa- nates, and dielectric properties of the scatterers in the environ- gation environment can be smaller than the actual environment ment must be measured and ported to the simulator code. Since proportionally. Hence, propagation measurements can be done these cannot be measured accurately, there remains a wide range very efficiently under laboratory conditions using a scaled model of uncertainties in the simulation result.
    [Show full text]
  • Channel Modeling for Fifth Generation Cellular Networks and Wireless Sensor Networks
    Michigan Technological University Digital Commons @ Michigan Tech Dissertations, Master's Theses and Master's Reports 2016 CHANNEL MODELING FOR FIFTH GENERATION CELLULAR NETWORKS AND WIRELESS SENSOR NETWORKS Amir Torabi Michigan Technological University, [email protected] Copyright 2016 Amir Torabi Recommended Citation Torabi, Amir, "CHANNEL MODELING FOR FIFTH GENERATION CELLULAR NETWORKS AND WIRELESS SENSOR NETWORKS", Open Access Dissertation, Michigan Technological University, 2016. https://doi.org/10.37099/mtu.dc.etdr/142 Follow this and additional works at: https://digitalcommons.mtu.edu/etdr Part of the Electromagnetics and Photonics Commons, and the Systems and Communications Commons CHANNEL MODELING FOR FIFTH GENERATION CELLULAR NETWORKS AND WIRELESS SENSOR NETWORKS By Amir Torabi A DISSERTATION Submitted in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY In Electrical Engineering MICHIGAN TECHNOLOGICAL UNIVERSITY 2016 © 2016 Amir Torabi This dissertation has been approved in partial fulfillment of the requirements for the Degree of DOCTOR OF PHILOSOPHY in Electrical Engineering. Department of Electrical and Computer Engineering Dissertation Advisor: Dr. Seyed A. (Reza) Zekavat Committee Member: Dr. Ossama Abdelkhalik Committee Member: Dr. Michael C. Roggemann Committee Member: Dr. Timothy J. Schulz Department Chair: Dr. Daniel R. Fuhrmann Dedication For my parents Hasan and Tahereh Contents List of Figures ................................. xi List of Tables .................................. xvii Acknowledgments ............................... xix Abstract ..................................... xxi 1 Introduction ................................. 1 1.1 Motivation . 1 1.2 Channel modeling for near-ground wireless sensor networks . 6 1.3 Channel modeling for fifth generation (5G) cellular networks . 8 1.4 Overview of dissertation . 11 2 Near-Ground Channel Modeling for Wireless Sensor Networks . 15 2.1 Introduction . 15 2.2 Derivation of the break points .
    [Show full text]
  • Short-Range Low-VHF Channel Characterization in Cluttered Environments Fikadu T
    IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 63, NO. 6, JUNE 2015 2719 Short-Range Low-VHF Channel Characterization in Cluttered Environments Fikadu T. Dagefu, Member, IEEE, Gunjan Verma, Chirag R. Rao, Paul L. Yu, Member, IEEE, Jonathan R. Fink, Member, IEEE, Brian M. Sadler, Fellow, IEEE, and Kamal Sarabandi, Fellow, IEEE Abstract—The lower VHF band has potential for low-power, State-of-the-art communication systems that operate in the short-range communications, as well as for geolocation applica- upper VHF through microwave bands suffer from significant tions, in both indoor and urban environments. Most prior work at attenuation and small-scale fading, as well as phase distor- low VHF focuses on longer range path loss modeling, often with one node elevated. In this paper, we study indoor/outdoor near- tion, caused by high levels of multipath [5], [6]. In a complex ground scenarios through experiments and electromagnetic wave environment at these frequencies, without line of sight (LoS), propagation simulations. These include the effects of indoor pen- multipath propagation is the dominant signal source between etration through walls and obstacles, as well as indoor/outdoor a transmitter (Tx) and a receiver (Rx), whereas the direct path cases, for both line of sight (LoS) and nonLoS (NLoS), at ranges signal is often extremely weak due to penetration loss. Major up to 200 m. Mounting our receiver (Rx) on a robotic plat- form enabled the collection of thousands of measurements over efforts have been devoted over many decades to design sophis- an extended indoor/outdoor test area. We measure the channel ticated multipath mitigation techniques, incorporating channel transfer function, employing bandpass waveform sampling, with coding and modulation schemes [7].
    [Show full text]